Printing plates and method of preparing same



et DEFENSIVE PUBLICATION UNITED STATES PATENT OFFICE Published at the request of the applicant or owner in accordance with the Notice of Apr. 11, 1968, 849 CG. 1221. Identiflcation is by serial number oi the application and the heading indicates the number of pages oi. specification, including claims, and of sheets of drawing contained in the application as originally died. The file of this application is available to the public for inspection; reproduction may be purchased for 30 cents per sheet.

Applications published under the Defensive Publication Program have not been examined as to the merits of alleged invention. The Patent Oflioe makes no assertion as to the novelty of the disclosed subject matter.

PUBLISHED OCTOBER 21, 1969 833 274 PRINTING PLATES AND METHOD OF PREPARING SAME Robert Newell Woodward and Joe Ellis South, both Eastman Kodak Company, Rochester, N.Y. 14650 Filed June 16, 1969. Published Oct. 21, 1969 Int. Cl. G03c 5/00; B44m 5 /00; G03f 7/02 U.S. Cl. 96-363 1 Sheet Drawing. 21 Pages Specification A printing plate is prepared by removing, by an etchbleach technique, developed, silver image-bearing portions of a hardened gelatino silver halide emulsion such as a negative, or positive or high contrast predominately silver chloride emulsion layer provided over a layer of an oleophilic synthetic resin such as polystyrene, polyvinylbutyral, acrylic esters, vinyl and vinylidene resins, cellulose esters, polyvinyl acetate, etc. The oleophilic resin layer may be organic solvent soluble and contain a coloring agent therein thus providing a printing plate containing its own ink supply. Alternatively, the resin layer may be used to provide oleophilic portions and the remaining hardened gelatin portions are hydrophilic.

Oct. 21, 1969 R. N. WOODWARD AL PRINTING PLATES AND METHOD OF PREPARING SAME Filed June 16, 1969 Fig i /-3 qwzxx x xx tmxfimxxw I FIG: 4

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